title: Biodegradable magnesium-based screw clinically equivalent to titanium screw in hallux valgus surgery: short term results of the first prospective, randomized, controlled clinical pilot study.
abstract: OBJECTIVE
  Nondegradable steel-and titanium-based implants are commonly used in orthopedic surgery. Although they provide maximal stability, they are also associated with interference on imaging modalities, may induce stress shielding, and additional explantation procedures may be necessary. Alternatively, degradable polymer implants are mechanically weaker and induce foreign body reactions. Degradable magnesium-based stents are currently being investigated in clinical trials for use in cardiovascular medicine. The magnesium alloy MgYREZr demonstrates good biocompatibility and osteoconductive properties. The aim of this prospective, randomized, clinical pilot trial was to determine if magnesium-based MgYREZr screws are equivalent to standard titanium screws for fixation during chevron osteotomy in patients with a mild hallux valgus.
  
  
  METHODS
  Patients (n=26) were randomly assigned to undergo osteosynthesis using either titanium or degradable magnesium-based implants of the same design. The 6 month follow-up period included clinical, laboratory, and radiographic assessments.
  
  
  RESULTS
  No significant differences were found in terms of the American Orthopaedic Foot and Ankle Society (AOFAS) score for hallux, visual analog scale for pain assessment, or range of motion (ROM) of the first metatarsophalangeal joint (MTPJ). No foreign body reactions, osteolysis, or systemic inflammatory reactions were detected. The groups were not significantly different in terms of radiographic or laboratory results.
  
  
  CONCLUSIONS
  The radiographic and clinical results of this prospective controlled study demonstrate that degradable magnesium-based screws are equivalent to titanium screws for the treatment of mild hallux valgus deformities.
authors.affiliation: Department of Orthopaedic Surgery, Hannover Medical School, Anna-von-Borries-Str,1-7, 30625 Hannover, Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Windhagen
authors.forename: Kerstin
authors.initials: K
authors.lastname: Radtke
authors.forename: Andreas
authors.initials: A
authors.lastname: Weizbauer
authors.forename: Julia
authors.initials: J
authors.lastname: Diekmann
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Noll
authors.forename: Ulrike
authors.initials: U
authors.lastname: Kreimeyer
authors.forename: Robert
authors.initials: R
authors.lastname: Schavan
authors.forename: Christina
authors.initials: C
authors.lastname: Stukenborg-Colsman
authors.forename: Hazibullah
authors.initials: H
authors.lastname: Waizy
mesh_terms: D020341:Absorbable Implants; D000328:Adult; D000368:Aged; D000497:Alloys / Q000737:chemistry / Q000378:metabolism; D001863:Bone Screws; D005260:Female; D006215:Hallux Valgus / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D008274:Magnesium / Q000737:chemistry*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D011859:Radiography; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*; D016896:Treatment Outcome
chemical_list: D000497:Alloys; D014025:Titanium; D008274:Magnesium